An electromechanical actuator (“EMA”) may be used in many applications, for example to actuate the primary flight control surfaces of an aircraft. In this and other applications, the electromechanical actuator may be housed within a unit and combined with an electronic control unit (“ECU”), which is configured to receive commands (e.g., from an aircraft computer) and process these to cause the electromechanical actuator to extend or retract. Typically, each electromechanical actuator unit may have an associated electronic control unit, and these may be combined in use into a single compact apparatus.
FIG. 1A shows a conventional electronic control unit 10, which may comprise two side portions 12, each housing electronic circuitry for controlling an electromechanical actuator unit 30 (see FIG. 1B). The electronic control unit 10 may further comprise a base portion 14 interconnecting the side portions 12, and comprising a connector 16 to provide power and electronic connections to the electromechanical actuator unit 30. The side portions 12 may comprise one or more connectors 18 to provide power and electronic connections to the electronic control unit 10, e.g., from a power source and/or central controller.
The electronic control unit 10 may comprise a first bracket 20 and a second bracket 22 configured to hold the electromechanical actuator unit 30 in use. A plurality of pins 24 may be positioned on the brackets 20, 22, which may be configured to cooperate with corresponding apertures 38 on the electromechanical actuator unit 30 (see FIG. 1B), so as to hold the electromechanical actuator unit 30 in position.
FIG. 1B shows the electromechanical actuator unit 30 in isolation, which comprises a housing 32 which houses the electric motor of the electromechanical actuator unit 30, and also functions as a heat sink using a plurality of fins 34. The housing 32 may comprise flanges 36 comprising apertures 38 that are each configured to cooperate with a corresponding pin 24 of the electronic control unit 10. The electromechanical actuator unit 30 comprises an actuating member 31 configured to extend and retract so as to actuate a component (e.g., a primary flight control surface of an aircraft).
The electromechanical actuator unit 30 comprises the housing 32, as well as an electromechanical actuator 40 and an end plate 42 that are configured to fasten to the housing 32 (e.g., via a plurality of fasteners 44) and enclose the components (e.g., motor) of the electromechanical actuator 40.
The electromechanical actuator unit 30 further comprises a connector 49 to provide power and electronic connections to the components (e.g., motor) of the electromechanical actuator 40 held within the housing 32, which connector 49 is configured to cooperate with the connector 16 on the electronic control unit 10.
FIG. 1C shows the electromechanical actuator unit 30 combined with the electronic control unit 10, and immediately prior to installing the electromechanical actuator unit 30 within the electronic control unit 10. In use, flanges 36 rest on respective portions of bracket 20, such that the electromechanical actuator 36 is configured to sit within the electronic control unit 10. To prevent unwanted movement of the electromechanical actuator unit 30 in use, pins 24 extends through apertures 38 when the electromechanical actuator unit 30 is installed.
Other types of actuator that use an associated electronic control unit are known, for example an electro-hydrostatic actuator (“EHA”), and these typically require a similar set-up to that shown and described in respect of the electromechanical actuator of FIGS. 1A-1C.
It is desired to provide a combined actuator and associated electronic control unit that has improvements to the connections therebetween, while reducing the weight and size of the combined apparatus.